The center contained the oldest part of V'Ger – Voyager 6, an unmanned space probe launched by NASA in the late 20th century. The entire vessel surrounding the Voyager probe was built by an unknown race of machine entities in order to help it complete what the latter interpreted to be its primary programming: "learn all that is learnable," and return that knowledge to its creator. During its journey, the probe came to think of itself as V'Ger after the only remaining legible letters from its original name (the "O", "Y", "A" and "6" on the nameplate being obscured from encounters with previous spatial hazards) and amassed knowledge to such a degree as to become self-aware.